For recording data on and reproducing data from an optical disk of a single spiral land/groove configuration, a header detector detects header regions on the optical disk, a PID error detector judges whether the address information read from the header regions is erroneous, using error detection codes, and detects the number of errors per sector. An error count comparator compares the number of errors per sector with a predetermined value, and a state judging circuit identifies the state of the optical disk device by causing transition to a higher or lower state according to the output of the error count comparator. The recording and reproduction are controlled according to the state thus identified.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A state detecting device for detecting a state of an optical disk device recording data in and reproducing data from an optical disk having a header information part for each sector, each header information part including a plurality of header regions each including an address region for holding address information and an address error detection region for holding an address error detection code for detecting an error in the address information read from the address region; said state detecting device comprising: a header detector detecting the header regions of a header information part; an error detector judging whether or not the error detection code read from the address error detection region included in each of the detected header regions indicates an error in the address information read from the corresponding address region, and holding the number of errors for the detected header regions of the header information part; an error count comparing unit comparing the number of errors held in the error detector with a predetermined number; and a state controller responsive to the output of the error count comparing unit for causing transition to a higher or lower state, to thereby identify the state of the optical disk device.
2. The state detecting device according to claim 1 , wherein said state controller causes transition to a higher state when the number of errors held in the error detector is not more than the predetermined value and causes transition to a lower state when the number of errors held in the error detector is more than the predetermined value.
3. The state detecting device according to claim 1 , wherein said state controller causes transition to a lower state when the number of errors held in the error detector continues to be more than the predetermined value for a predetermined number of sectors.
4. The state detecting device according to claim 1 , wherein said header detector detects the header regions using a first header detection window generated based on the address information, or a second header detection window generated based on a header position detection signal indicating the arrangement of the plurality of header regions contained in one sector.
5. The state detecting device according to claim 4 , wherein said header detector detects the header regions using said first header detection window when the optical disk device is in or above a predetermined state, and detects the header regions using said second header detection window when the optical disk device is below said predetermined state.
6. An optical disk device recording data in and reproducing data from an optical disk having a header information part for each sector, each header information part including a plurality of header regions each including an address region for holding address information and an address error detection region for holding an address error detection code for detecting an error in the address information read from the address region, said optical disk device comprising: an optical head for writing data on and reading data from an optical disk device; a header detector detecting the header regions of a header information part from the data read by said optical head; an error detector judging whether or not the error detection code read from the address error detection region included in each of the detected header regions indicates an error in the address information read from the corresponding address region, and holding the number of errors for the detected header regions of the header information part; an error count comparing unit comparing the number of errors held in the error detector with a predetermined number; a state controller responsive to the output of the error count comparing unit causing transition to a higher or lower state, to thereby identify the state of the optical disk device; and a recording/reproducing means for controlling the recording and reproducing operation of the optical disk device in accordance with the result of the judgment by said state controller.
7. The optical disk device according to claim 6 , wherein said recording/reproducing controller permits recording of data on and reproduction of data from the optical disk when said optical disk device is in or above a predetermined state, and prohibits the recording and reproduction when said optical disk device is below said predetermined state.
8. The optical disk device according to claim 6 , wherein said state controller causes transition to a lower state when the number of errors held in the error detector continues to be more than the predetermined value for a predetermined number of sectors.
9. The optical disk device according to claim 6 , wherein said header detector detects the header regions using a first header detection window generated based on the address information, or a second header detection window generated based on a header position detection signal indicating the arrangement of the plurality of header regions contained in one sector.
10. The optical disk device according to claim 6 , wherein said header detector detects the header regions using said first header detection window when the optical disk device is in or above a predetermined state, and detects the header regions using said second header detection window when the optical disk device is below said predetermined state.
11. An optical disk device recording data in and reproducing data from an optical disk having a header information part for each sector, each header information part including a plurality of header regions each including an address region for holding address information and an address error detection region for holding an address error detection code for detecting an error in the address information read from the address region; a front part of said header information part being shifted from the center of a track by half a track pitch in one of a radially inward and radially outward directions, and a rear part of said header information part being shifted from the center of a track by half a track pitch in the other of a radially inward and radially outward directions, said optical disk device comprising: an optical head for forming a light spot for writing data on and reading data from an optical disk; an analog signal processor responsive to the output of said optical head for producing a reproduced signal and a tracking error signal; a header detector detecting the header regions from the data read by said optical head; an error detector judging whether or not the error detection code read from the address error detection region included in the detected header region indicates an error in the address information read from the address region, and holding the number of errors for one sector; an error count comparing unit comparing the number of errors held in the error detector with a predetermined number; a state controller responsive to the output of the error count comparing unit for causing transition to a higher or lower state, to thereby identify the state of the optical disk device; and a window generator generating a detection window signal or a timing signal based on the address information contained in the detected header region, when the result of judgment by said state controller indicates that the optical disk device is in or above a predetermined state, and for generating a detection window signal or a timing signal based on address information which indicates the position within the sector and is generated based on the output of said optical analog signal processor at the time when the light spot passes the header region, when the state indicated by said state controller indicates that the optical disk device is below said predetermined state.
12. The optical disk device according to claim 11 , wherein said header detector detects said header regions using a header detection window generated by said window generator.
13. A method of detecting a state of an optical disk device recording data in and/or reproducing data from an optical disk, said optical disk including a recording area divided into a plurality of sectors each having a header information part, each header information part including a plurality of header regions each including an address region for holding address information and an address error detection region for holding an address error detection code for detecting an error in the corresponding address information, said method comprising: detecting a header information part corresponding to a sector of said optical disk; reading address information and an address error detection code from each of a plurality of header regions in the detected header information part; judging for each of said plurality of header regions whether said address error detection code indicates an error in the corresponding address information; determining a number of errors for said detected header information part; and changing said state of said optical disk device, based on said number of errors in said detected header information part, to a higher state or a lower state.
14. The method according to claim 13 , wherein said state of said optical disk device represents the degree to which said optical disk device can accurately read said header information part.
15. The method according to claim 13 , further comprising: selectively prohibiting said optical disk device from recording to or reproducing information from a sector of said optical disk in accordance with said state.
16. The method according to claim 13 , wherein said changing step changes said state of said optical disk device to a higher state when said number of errors is not more than a predetermined value and changes said state of said optical disk device to a lower state when said number of errors is more than said predetermined value.
17. The method according to claim 13 , wherein optical disk device detects header regions using a first header detection window or a second header detection window, depending on said state of said optical disk device.
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February 2, 1999
July 16, 2002
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